MODIFICATION OF CARBON PASTE ELECTRODE WITH MOLECULARLY IMPRINTED POLY(GLUTAMIC ACID) FOR VOLTAMMETRIC DETERMINATION OF DOPAMINE

• Main Author: RIZKY ARIEFA ( NIM : 10512052 ), DHIYAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21705
• Institution: Institut Teknologi Bandung

Dopamine is one of important compound in body fluid acting as neurotransmitter. Normal concentration of dopamine in human body range from 10-7 to 10-3 mol/L. Higher level of dopamine may cause schizophrenic syndrome while lower level of dopamine may cause Parkinson disease. Interference from uric acid along with ascorbic acid is still the main problem in voltammetric determination of dopamine besides the sensitivity of the method for very low dopamine concentration. In this study, carbon paste electrode (CPE) is modified by using moleculary imprinted poly(glutamic acid) to overcome the problems. The surface of CPE was modified through electropolymerization of glutamic acid from phosphate buffer solution pH 7 containing 0.4 mM glutamic acid and 0.1 mM dopamine. Cyclic voltammetry technique was used for the electropolymerization processes. Six cycles of potential in the range of -800 mV to 1800 mV with scan rate of 100 mV/s was applied to electropolymerize glutamic acid. Repeated measurement (n=30) of 0.05 mM dopamine gave relative standard deviation (RSD) of 3.4% and the reproducibility of 5 different electrodes have RSD of <br /> <br /> <br /> <br /> 2.2%. Calibration curve shows good linearity in concentration range of 2 &#956;M – 100 &#956;M with detection limit of 1.65 &#956;M. Determination of dopamine in spiked urine sample using differential pulse voltammetry method resulted in percent recovery of 92.6% - 101.5%. <br />